Method of and apparatus for annealing glassware



Oct. 1'8, 1938. D. G. MERRILL 2,133,784

METHOD 0F AND APPARATUS FOR ANNEALING GLASSWAE Filed sept. 22, 19:56

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METHOD OF ANO APPARATUS FOR ANNEALING GLASSWARE I Filed Sept. 22, 1936 r2 Sheets-Sheet 2 Tim-rn vento:

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Patented Oct. 18, 1938 UNITED STATES METHOD OF AND APPARATUS FOR. ANNEAL- IVNG GLASSWARE Donald G. Merrill, West Hartford, Conn., assigner to Hartford-Empire Company, Hartford, Conn., a corporation of Delaware Application September 22, 1936, Serial No. 101,926

l 23 Claims.

This invention relates to a method of and an apparatus 'for annealing glassware and more particularly to a method of operating and the constructing of glassware annealing lehrs in which the temperature of the ware is controlled by products of combustion or other heated media which pass longitudinally of the tunnel in a manner to supply heat by radiation to the ware passing therethrough and at' the same time in such fashion that a part of the heat of the media is transferred to air, which is thereafter injected into the tunnel in such manner as to create therein predetermined desired circulatory currents, the direct radiant and indirect heat supplied to the tunnel and the circulatory currents therein controlling the temperature gradient of the ware during its passage throughout the annealing portion at least of the tunnel.

lMy present invention comprises a continuation in part of my prior and copending application, Serial No. 66,611, led March 2, 1936, for- Method of and apparatus for annealing glassware.

I Among the objects of the present invention are to provide a lehr of the general type disclosed in my said copending application, but in which products of combustion, which may be passed in heat transferring relation with the ware in the lehr, are maintained out of direct contact with such ware. Thus, for example., any desired fuel, including oil, may be employed in the generation of the products of combustion without injuriously aiecting the ware being annealed. This is furtherv sages, and indirectly to heat air which is later circulated in the tunnel by utilizing certain at least of the passages as heat interchangers. is a further object to so locate certain atleast of the muilie passages as to supply heat to the portions of the tunnel where it is principally required, namely, adjacent to the sides at the lower portion of the tunnel, so as to offset heat losses through the sidewalls and to-maintain substantially uniform temperatures transversely of the tunnel. r

A further object of the present invention is to provide in a lehr ofthe character hereinabove set forth for the control of temperatures laterally of the lehr at various portions thereof, either to accommodate non-uniform lateral loading oi' the lehr and consequent desired non-uniform lateral heating and/or cooling thereof or to provide .for the establishment and maintenance of uniform conditions laterally of the lehr where the normal tendency would render these conditions non-uniform.

Other and more detailed objects of the present invention will become apparent from the following specification and appended claims, when taken in connection with the accompanying drawings, in which: Y

Figure l is a view substantially in longitudinal vertical section on the line I-I of Fig. 3 and with a part at the center broken out, showing the hotter or annealing portion of a lehr embodying my invention;

Fig. 2 is a view similar to Fig. 1 of thecooli'ng portion of the lehr taken substantially on the line 2-2 of Fig. 6; v

Fig. 3 is a view of the hotter portion of the lehr in horizontal section taken substantially on the.

line 3-3 of Fig. 1; l

Fig. 4 is a view in .transverse vertical section taken substantially on the line l-Iof Fig. 1;

Fig. 5 is a view in transverse vertical section taken substantially on the linel 5-5 of Fig. 2;

Fig. 6 is 'a view in transverse vertical section taken substantially on the line 6-6 of Fig. 2;

Fig/'1 is a view in transverse vertical section taken substantially on the line 'l-'l of Fig. 2;

Fig. 8 is a fragmentary view of. certain of the piping associated -with the lehr in horizontal section taken substantially on the line` 8-8 of Fig. 2;

and

Fig. 9 is a fragmentary detail view partly in vertical section on the line 9--9 of Fig. 3.

The lehr which I have chosen to illustrate in the accompanying drawings is constructed with or upon a rigid structural frame work including longitudinally extending channel members (not shown), which are connected at intervals along the lehr by transverse channels I, these channels being supported upon suitable 'legs '2, which in turn may rest upon the oor of the. plant in which the'lehr is installed or upon any other suitable support. If desired, suitable rollers or castors (not shown) may be' employed in association with each of the legs or supports. I have, however, not illustrated any such means as they are now in common use in the art and per se involve no invention on my part. I

The hotter portions of the lehr tunnel are built upon a structural frame work including the channels I and Within a casing, usually of sheet metal, and comprise insulating material 3 and relatively rigid heat resistant blocks 4, which form the sides and top. of the tunnel, special provisions being made as hereinafter more fully described for forming the bottom of the tunnel 5 in the hotter portion thereof. The cooler por-v 3, 1925. As the driving means for the belt 6 form Il in the cooler portion thereof, as seen in Fig. 2. These angles and channels are suitably secured to longitudinally extending structural members as more particularly described in my'copending application above referred to and including, for

example, angles 9 (Fig. 5) or Z-shaped members Il! (Fig. 4). v` The vbelt supporting structure is preferably formed in a plurality of independently removable sectionsas disclosed in my said copending application. This structure is supported upon and may be suitably secured to longitudinally extending channels I I. The belt supporting means thus' provides .adequate support both laterally and longitudinally for the belt 6, while permitting free flow of tunnel atmosphere therethrough land about all sides of the-ware being transported through the tunnel.

Means are provided for supplying heat to the lehr in a manner which is in eiect muilled. 'I'his permits of the use of any desired types of fuel including those which will produce combustion products' of the type which it is desired to keep out of contact with the ware being annealed, for example, certain types of fuel oils. It also permits the use of more eftlcient combustion, methods, as all theJfuel may be burned at one place, For-this purpose there is provided adjacent to the forward end of the lehr a combustion chamberf-,IZ- .'(Figs. 1 and 3) to which fuel ora mixtureof fuel and air is supplied through a burner diagrammatically illustrated at I3, the burning fuel and the products of combustion owing in the direction of the arrows in Figs. 1 and 3; 'I'he combustion chamber I2 debouches into va. muille chamber I3l substantially coextensive in width -with the tunnel, through a passage Il, there being a baille I5 'in the chamber I3* opposite the passage I4. -The combusof the roof of the chamber I3* (as shown) may comprise a corrugated member I6, which may be of thin ceramic or metallic material andwhlch is supported at intervals upon pillars I1 intermediate the sides of the lehr. The right hand f end of the chamber I3* as shown in the drawings is formed of an inclined refractory wall generally indicated at It'and a vertical wall formed in part of `refractory material and in part of a structural metal member shown at I9 (see Fig. 9).

'I'he products 'of combustion pass from the chamber I3* through two longitudinally extending passages 20 formed as relatively large diameter pipes, these passages or pipes'being located as shown adjacentto the floor or bottom of the tunnel, vertically below the path of the ware and-adjacent to the side walls of the lehr. As will be obvious from the drawings, the pipes 20 are in direct heat radiating relation with they ware passing through' the tunnel up to the jog 2| in the tunnel bottom, `which is located substantially at the end of the annealing zone proper of the lehr,that is, the point along the lehr where it is contemplated that the ware will be cooled at least down to its. low annealing temperature.

The low annealing temperature of glassware is that temperature below which permanent strains cannot be-introduced or reintroduced into the ware, due to the fact that glass below this temperature is so rigid that no further molecular rearrangement can '"take place therein. Below this temperature temporary strains may be introduced into the ware, but these will disappear upon the ware being finally cooled. However,

any permanent strains which have not been removed at the time the ware hasv reached this "low annealing temperature" will be jpresent in the finished articles to the same extent that they are present in the ware when it passes through this low annealing temperature.

The passages or pipes 2l pass through a part of the insulation 3 surrounding the tunnel beyond the jog" 2l for a certain distance, after which they emerge to the'outside as best shown in Fig. 2 and terminate in pipe fittings best shown at 22, Fig. 8. The products of combustion thence pass laterally through' nipples 23 to vertically extending T-members 24, Fig. 6, whichto afford a lateral control of the heat supplied y to the lehr.

Associated with the fire box I 2 or more particularly with the chamber |30, there is an inlet 21* for air from .the outer atmosphere ito provide w a desired amount of secondary'air and/or to provide for the dilution of ,the products of combus- -tion to bring them to a desired temperature. The

inlet 21* communicates with a laterally extending passage indicated in dotted lines in Fig. 3

Abe directed more or less to one side or the other selectively. Such a means is disclosed inthe patent to Wm. T. Honiss, No. 1,849,037, granted March 8, 1932. l

For insuring a positive draft through the passages just described, there -is preferably provided some suitable draft inducing means. present instance this means comprises ejector nozzles 29 associated with the members 24 and 25 on each side of the lehr and supplied with air through passages 30 and 3| from air supply passages 32 and 33 (Fig. 2) leading from a-su'itable fan 34 and controlled by dampers associated withhandles 35 (Figs. 2 and 8) to afford' independent control for the two sides of the lehr. The fan 34 may be driven from any suitable prime mover, which in the usual case com.- prises an electric motor (not shown).

Means are preferably provided for preheating air which is thereafter to be introduced into the tunnel in a manner more specifically hereinafter to be described. The air preheating not only serves to impart heat to the air by heat interchange, but also serves to control the temperature gradient of the hot products of combustion which pass along the lehr as aforesaid. For this purpose a branch pipe 36- (Figs. 2 and 8) leading from each of the air supply pipes 3| communicates with a concentric pipe 31 in and extending longitudinally of each of the passages or pipes 20. The pipes 31 communicate at their ends nearer the Ware-entering end of the lehr with respective side chambers 38 (Figs. 3 and 9) formed as portions of a divided header 39, the

division being shown at 40 (Fig. 3). 'Associated I with each of the chambers 38 are a plurality of nozzles 4l (Figs. 1, 3 and 9). Flow of air through the nozzles 4| is controlled independently for each side of the lehr by the provision of dampers 42, each of which lscontrolled by a handle 43.

The remainder of the preheated air is conducted from the chambers 38 into longitudinally extending pipes 44, one of which is associated with each of these chambers. The pipes 44 are' provided at spaced intervals therealong with nozzles 45. The pipes 44 extend longitudinally of the lehr and substantially up to the jog 2| in the bottom thereof and adjacent to the center of the tunnel beneath the path of the' ware therethrough (Figs. 3 and 4). The nozzles 45 are arranged to direct jets of air laterally, and as shown in Fig. 4, slightly upwardly Ain respect to the horizontal, the air in the tunnel5 being circulated thereby through passages 46 formed' by divergingyertical walls y41 and horizontal walls 48 which may be formed of tiles. as shown. The circulation of air induced by the jets from nozzles 45 is laterally from the center toward the sides of the tunnel and around the pipes 2|), whichconduct the h ot products of combustion as aforesaid, so that the circulating air is further heated at this point. The circulating heated air then flows upwardly along the sides of the tunnel to oppose the normal tendency for loss of heat through the sides, thence toward the center above the path of the ware, and thence downwardly through the path of the ware tov be recirculated by the inductive action of the jets from the noz` zles 45. This circulation is shown by the arrows l In the:

.path of the ware tunnel where it might interfere with. the maini tenance of a desired temperature gradient. Another part of this air returns rearwardly of the tunnel and is recirculated by the inductive action fromthe jets from the nozzles 4| and in an orbital path generally longitudinal of the tun-v nel. Thus, there isin the present lehr a circulation in the hotter portions of the tunnel substantially similar to that disclosed in my said copending application, with this difference that the medium being circulated in the present instance is air and does not contain any products. of combustion, whereas in my copending application the products of combustion were themselves circulated and recirculated in the tunnel.

Also, there Will not only be a lateral control of the air supplied to the tunnel toward the entering end thereof through the nozzles 4|, but also there is providedy according to my invention a lateral control of the circulations trans'- versely of the tunnel -caused bythe inductive action of the nozzles 45. There may be for this details of the structure of Fig. l2. In order to render the present description complete, this cooling means will be brieily described.

Cooling is generally effected by the provision of means by which cooling air is circulated in directions generally transverse of the tunnel and in substantially orbital paths, which may be considered as starting adjacent to the upper side corners of the tunnel, thence toward the center above the path of the Ware, where the air is deflected downwardly through the path of the ware, thence again toward the sides of `the tunnel and thence upwardly to be recirculated by the inductive action of the jets by which cooling air is continuously introduced into the tunnel. In association with this induction and circulating means, there are means provided at intervals longitudinally of the tunnel for drawing off controllableamounts of air from the circulation as aforesaid, these means being-located above the and substantially centrally of the tunnel.

More specifically, there is provided along each of the upper side corner portions of the tunnel a Ilongitudinally extending pipe 50 (Figs. 5, 6 and 7) With these pipes there are associated a plurality of jet nozzles 5|, part of which'are directed `at to the axis of the associated pipes and transversely of the tunnel, so as to direct air toward the centerthereof, while some of which may be directed also generally transversely of the tunnel, but slightly toward the entering end thereof, so as to assist in inducing an inflow-of atmospheric airat the coolerror exit end of the tunnel.

Associated with the roof of the tunnel andin y n.'53 are stationary in position and have no movable parts, these deflectr members having their inclined lateral side portions spaced a predetermined distance from the roof of the tunnel, as

. best shown in Figs. 2 and 5, lto provide openings 75 56 into the interior of the deector members Afrom which' the air may be withdrawn through outlet ports 51 and 58 associated with deflectors 52 and 53 respectively.v These outlet ports are respectively controlled bymating damper members` 58 and 60, which may be controlled by suitable manual operating means as indicated at 6|, Fig. 5. The defiector 52 has a longitudinal extent greater than that of the outlet port 51 associated therewith' and in practice extends several feet along the lehr toward the entrance end thereof. The defiector member 53 is of substantially the same longitudinal extent as the port 58 associated therewith. It will "be understood that the amount of air withdrawn through the ports I 51 and 58 maybe controlled by the dampers 58 and 60,\so as to control the temperature gradient or the cooling in the portions of the lehr with which deflector members 52 and 53 are associated.

Deflector members 54 have upper portions 62 of their side walls pivotally connected to the lower stationary portions thereof and arranged to be adjusted in respect thereto to control the width of the opening between these hinged portions and the roof of the tunnel and thereby to control the amount of air deflected from the circulation in the tunnel. For this purpose the hinged portions 62 have associated therewith rigid arms 63,

. which are connected by links 6I to cranks 65 seand '7.C

By the use and proper adjustment of the cool-l ing means provided and specifically by the control of dampers 69 in the vertical portions of pipes 32, which conduct air to the longitudinally extending pipes 50, I am enabled independently laterally to control the degree'of cooling effected by the cooling means in the cooling portion of the tunnel. Furthermore, due to the fact that some of the nozzles 5l, particularly those adjacent to the exit end of the lehr, are inclined somewhat forwardly, air will be induced into the exit end of the tunnel and caused to flow counter-currently in respect to the ware, so asto provide the desired typeof cooling. Also, due to the fact that the coolest airin the circulation is caused to ow toward 'the center and thence downwardly through the ware at the regions spaced from the side walls thereof, the ware nearer the center of 'the belt may be maintained at the same temperature as the ware at the sides, which tends normally to cool more quickly.

Thus, I have provided4 a lateral cdhtrol'of the cooling, which in conjunction with the lateral control provided for the heating means and circulatingv means in the hotter portions of the lehr,

affords a lateral control substantially throughout A the length or the lehr. Thus, for example, if one side of the lehr-is loaded with ware of a diilerent average weight than thatr loaded on the other side, the annealing conditions may be so adjusted in respect to the weights of the ware on the two sides of Lthe belt that all the ware may be properly and uniformly annealed. On lthe other hand, ii' the normal conditions` transversely of the lehr would tend to be dissimilar, while the loading of the ware on the belt is substantially uniform from side to side, I am enabled to obtain uniform tmperature conditions transversely of .the lehr. Such a condition may arise, for example, when the lehr is positioned adjacent to a'hot body on one side, as a glass melting tank, while the other side. is closed to a relatively cold region, as for example the side wall of the factory. Under these circumstances the normal rate of heat dissipation through the hotter wall is less than that through the colder wall and it is desirable that the heating and cooling of the lehr be so adjusted as to compensate forthis diierence. This may be eiected by the use of apparatus constructed in accordance with the present invention.

In the hotter portion of the lehr the region or zone above the ilre box I2 and the mume chamber I3* may be considered as a soaking zone, i. e.,

a zone where it is desired that the ware be brought to and maintained at a given temperature for the release of permanent strains. The next relativelylong zone of the lehr may be considered as that from the end ofthe munie chamber l 3a substantially to the jog 2|. During its passage through this zone, the ware is allowed to cool' through its critical temperature range, that is, down' to the low annealing temperature" as dened above. 'I'his may be termed the annealing zone of the lehr. The remainder of the lehr is primarily devoted to the cooling of the ware down to the desired handling temperature. I-Ierethe temperature gradient is controlled as to cool the ware at a rate usually somewhat faster than that in the" annealing zone in `order that the device operate emciently, while at the same time keeping therate of cooling within the permissive limits, such that the ware is at no time subjected to such heavy temporary strains as might cause rupture of the ware being annealed. This cooling of the ware may be advantageously eected by the proper control of the transverse circulation of cooling airas just described, sufflcient air being withdrawn from the tunnel at the various zones through the ports 51, 58 and 68, so that a desired cooling gradient is provided.

While I have shown for the purpose of illustrating my present invention but one embodiment thereof, I contemplate that many changes mayv be made therein and equivalents substituted for individual parts or features herein specifically described. I do not wish to belimited, therewith the ware, preheating air by heat derived from said oid medium, and thereafter introducing and recirculating such air in and generally transverselylof the tunnel through the path of the ware and in contact therewith to control the temperature gradient of the ware passing through the tunnel.

2. 'I'he method of annealing glassware, which comprises passing the/ware through an elongateA lehr` tunnel, .passing a relatively highly heated.

sol

fluid medium longitudinally through a portion of' the tunnel in heat-transferring relation with the ware passing therethrough but out of contact with the ware, and recirculating air in the tunnel by introducing air thereinto'in a longitudinally extending median zone of the tunnel below the path of the ware and in directions such that the air is introduced into the tunnel in such zone the highly heated fluid medium flowing longitudinally of the tunnel for thereby controlling the temperature gradient in the ware;

3. 'I'he method of annealing glassware, which comprises passing the ware through an elongate lehr tunnel, generating products of combustion and passing such products in muliled passages longitudinally of a portion of the tunnel in heatradiating relation with the ware passing therethrough, preheating air by heat derived from the products of combustion, and thereafter introducing such preheated air into the tunnel below and centrally of the path of the ware and in the direction of the sides of the tunnel to cause recirculation of heated air in the tunnel ln paths passing from the point of introduction of the air to the sides of the tunnel, thence up the sides,

thence toward the center of the tunnel above the path of the ware and thence downwardly spaced from the sides of the tunnel and through the path of the ware to the zone of introduction of the air, the air during its circulation as aforesaid impinging upon and absorbing heat from the muiiled passages through which the products of combustion are being conducted as aforesaid.

4. The method of annealing glassware, which comprises' passing the ware through an elongatev lehr tunnel, passing products of combustion longitudinally of the tunnel below the path of the ware and adjacent tothe sides of the tunnel to supply heat primarily to the tunnel adjacent the sides thereof, while preventing contact between the products of combustion and the ware passing through the tunnel, recirculating air in the tunnel by introducing air thereinto below the path of the ware and toward the opposite sides of the tunnel to absorb heat from the products of combustion passing along the sides of the tunnel, thence to flow up the sides and toward the center of the tunnel above the path of the y ware, thence downward through the path of the ware in a longitudinal median zone spaced from the sides of the tunnel to be recirculated, and thereby controlling the temperature gradient in the ware throughout a portion at least of its path through the tunnel.

5. The method of annealing glassware as defined in claim 2, further characterized bythe step of introducing air into the tunnel below the path of the ware and above a portion of the tunnel along which the highly heated fluid medium tunnel.

6. Themethod of annealing glassware, which comprises passing the ware through an elongate tunnel, passing a relatively highly heated uid medium longitudinally of a portion of the tunnel in heat-transferring relation with the ware passing therethrough but out of contact with the ware, preheating air by heat derived from said fluid medium, and thereafter introducing such s air into the tunnel while causing the-recirculation of a part of such air in and generally transversely of the tunnel through the path of the Ware and in contact therewith, and causing a flow of another part'of such air into the tunnel below the path of the ware and toward the entrance end of the tunnel to opposeA inflow of atmospheric air into the entrance end of the tunnel.

7. The method of annealing glassware, whichA thence up the sides, toward the center of the tunnel above the path of the ware, and thence downwardly through the path of the ware to be recirculated, passing other air intov the tunnel below the path o f the ware in a zone nearer the aoy said and in a direction toward the entrance end i of the tunnel to oppose inflow of atmospheric air into the entrance end of the tunnel and independently controlling the temperature gradient in the tunnel on opposite sides of the median line thereof.

8. The method of annealing glassware. which comprises passing the ware through an elongate lehr tunnel, passing a relatively highly heated uid medium longitudinally of the tunnel in paths below the level of the path of the ware therethrough and adjacent to the sides of the tunnel vwhile maintaining suchmedlum out of contact with the ware passing through thetunnel, preheating air bycausing lit to flow longitudinally of the tunnel in heat-interchanging relation to thepaths of the fluid medium asaforesaid and counter-current thereto, and thereafter introducing such preheated alrinto the` tunnel in such manner that it will flow in paths enveloping the ware passing therethrough.

9. The method of annealing glassware, which comprises passing the ware through an elongate lehr tunnel, passinghighly heated gases adjacent to and below the path of the"ware in heattransferring relation therewith during a portion at least of the ware path through the tunnel, the path of the gases adjacent to an initial zone for the 'ware adjacent to the entrance end of the tunnel being substantially coextensive laterally with the-tunnel and thereafter in a next zone annealing range, adjacent to the sides only of the tunnel, and creating substantially transverse recirculations of heated air in the tunnel in the annealing zone for the`ware and in paths passing through the path of the Ware and past the paths of the highly heated gases as aforesaid to provide a desired temperature gradient for the ware.

10. The method of annealing glassware, which comprises passing the ware throughan elongate 4lehr tunnel, passing a relatively highly heated fluidmedium longitudinally of the portion of the tunnel in heat-transferring relation with the ware passing therethrough but out of contact with the ware, introducing air into the tunnel ,in directions transverse to and below the path of the ware 'l0 in a longitudinally median zone spaced from the sidesof the tunnel, and setting up inthe tunnel a super-atmospheric pressure by the continuous introduction of air as aforesaid, whiclrtends to prevent inilow of relatively cold atmospheric air at the entrance endof the tunnel. h

1l. Apparatus for annealing glassware, comprising an elongate tunnel, means for conveying glassware therethrough, mume means for passing relatively highly heated gases longitudinally of the tunnel and in heat-transferring relation with the ware passing therethrough, heatinterchanging means including s air passages withinthe gas passages of the last-named means for preheating air, and means for directing the air thus4 preheated into the tunnel to envelope the glassware passing therethrough.

'12. Apparatus for annealing glassware, comprising an elongate tunnel, means 'for conveying glassware therethrough, munie means for pass- .30 ing relatively highly heated gases longitudinally of the tunnel and in heat-transferring relation with the ware passing therethrough, heat-interchanging means associated with said muille means g,

for prheating air, and means for directing air thus preheated into the tunnel belowthe path of the ware and towardthe entrance eind of 'the tunnel in such' manner as to oppose any tendency of atmospheric air to' iiow into th entrance end oi' the tunnel.

n 13. Apparatus for annealing glassware, comprising an elongate tunnel, means for conveying glassware-therethrough, munie means for passing relatively highly heated gases longitudinally of the tunnel and in heat-transferring relation "'45 with the ware passing therethrough, heat interchanging means associated with said munie means for preheating air, and means for directing such preheated air into the 'tunnel from below the path of the ware -and toward the sides thereof to cause a recirculation of air toward the sides below the path of the ware, thence up the sides and toward the lcenter of the tunnel above the path of the ware and thence downwardly through the path of the ware to be recirculated by the air being introduced into the tunnel.

14. Apparatus for annealing glassware, com# prising an elongate tunnel, means for conveying glassware therethrough, munie means for passing relatively highly heated longitudinally of co the tunnel and in heat-transferring relation with the ware passing therethrough, heat-interchang ing means associated with said muiiie means for preheating air, means for directing a portion of the air so preheated into the tunnel' from belowI g the path of the ware and directed toward the en- `trance end of the tunnel, means for adjustably controlling the amount of air so introduced into the tunnel, and means for directing another independently controllable amount of air into the 10 tunnel in such manner as to cause a recirculation thereof in paths generally transverse of said tunnel in a zone spaced further from the entrance end of the tunnel than that into which the rst- A, named portion of the preheated airis introduced. u 15. vApparatus for annealing glassware. comprising an elongate tunnel, means for conveying glassware therethrough, munie means for passing relatively highly heated gases longitudinally of the tunnel and in heat-transferring relation with the ware passing therethrough, heat-interchang- 5 ing means associated with said muiile means for preheating air, means for introducing a portion. of the air so preheated into the tunnel in a rst zone starting at the entrance end thereof and below the path of the ware in a-direction toward the 10 entrance end of the tunnel, means for introducing another portion of the air so preheated into the tunnel in asucceeding zone from the entranceend thereof and in directions generally transverse of the tunnel, and means for independently 15 controlling the flow of all the air introducedinto the tunnel as aforesaid on opposite sides of the' longitudinal median line of the tunnel. q

A 16. Apparatus for annealing glassware, comprising an "elongate tunnel, means forgconveying 20 -glassware therethrough, said tunnel including a first soaking zone starting at the entrance end in passing through which the temperature of the war'e is brought to and maintained at a desired point, a second annealing zone in passing through 25 which the ware is caused to drop in temperature throughout its annealing range, and a cooling znein which the ware i s cooled to a desired point,

a muiiie, substantially coextensive in width withl the tunnel associated with the soaking zone there- 30 of and below the path of -the ware, passagesextending from the muille below the level of the path of the ware and adjacent t0 the lateral sides of the tunnel, means for supplying products of 'combustion to said muiile and said passages, means as- 88 sociated with -some at least of the conducting means for the products of combustion for preheating fair prior to the introduction of suchl air into the tunnel, and means for thereafter introducing air so preheated into the tunnel in such 40 passing through which the temperature of the f ware is brought to and maintained at a desired point, a second annealing zone in passing through which thel ware is caused to drop intemperature throughout its annealing range, and a cooling zone in which the ware is cooled to a desired point, a muiile substantially coextensive in width with Athe tunnel associated vwith the soaking zone l 'thereof and below the path of the ware, passages extending frormthe muiile below the level of the path of the ware and adjacent to the lateral sides of the tunneLmeans for supplying products'of combustion to said' muilie and said passages,

means associated with some atleast of the conn'.

ducting means forthe products of combustion for preheating air prior to the introduction of such air into the tunnel, and means for introducing a part at least of the airso preheated into the tunnel y above the muille means in the soaking zone ano below the path of the -ware in a direction toward the entrance endof the tunnel and thereby setting up a gaseous current in the tunnel tending to oppose the iniiow of atmospheric air into the entrance end ofthe lehr tunnel. f 70 18. Apparatus for annealing glassware, comprising an elongate tunnel, means for conveying glassware therethrough. said tunnel including a iirst soaking zone starting at the entrance end in passing through which the temperature of the u Ware is brought to and maintained at a desired point, a second annealing zone in passing through which the ware is caused to drop in temperature throughout its annealing range, and a cooling zone in which the ware is cooled to a desired point,

a muie substantially coextensive in width with ing zone thereof below the path of the ware. and v toward the lateral sides of the tunnel to absorb heat from said passages and thence to ilow up the sides of the tunnel, towardthe center thereof above the path of the ware, and thence downwardly through the path of the ware to be recirculated by the air being introduced into the tunnel as aforesaid.-

19. Apparatus for annealing glassware, comprising an elongatetunnel, means for conveying glassware therethrough, said tunnelincludng a rst soaking zone starting at the entrance end in passing through which the temperature of the ware is brought toand maintained at,-a desired point, a second annealing zone in passing through which the ware is caused to drop in temperature throughout its annealing range, and a cooling zone. in which the ware is cooled to a desired point, a muffle substantially coextensive inwidth with the tunnel associated with the soaking zone thereof and below the path of the ware, passages extending from the muie below the level of the path of the ware and adjacent to the lateral sides of the tunnel, means for supplying products of combustion to said mule and said passages,

air pipes within said passages, means for causingv a counter-current flow of air through said pipes to provide for the preheating of the air in the heat interchanger so formed, and means for introducing the air so preheated into the tunnel and below the path of the ware in suchmanner that a portion of the air is introduced in adirection toward the entrance end of the tunnelv above said mulle and another portion is introduced into the annealing zone of the tunnel in directions toward the latter sides of the tunnel to cause the circulation of air substantially transverse of the tunnel.

20. Apparatusfor annealing glassware, comprising an elongate tunnel, means for conveying glassware therethrough, said tunnel including a first soaking zone starting at the entrance end in passing through which the temperature of the ware is brought to and maintained at a desired point, a second annealing zone in passing through which the ware is caused to drop in temperature throughout its annealing range, and a cooling zone in which the ware is cooled to adesired point, a muflle substantially coextensive in width with the tunnel associated with the soaking zone thereof and below the path of the ware, passages extending from the 'muiiie below the level of the path of the ware and adjacent to the lateral sides of the tunnel, means for supplying products of combustion to said muille and said passages, air pipes extending within said passages, means to cause a ow of air 'through said pipes to effect a counter-current preheating of the air,

and means to introduce the air so preheated into the tunnel in the annealing zone thereof below the path vof the ware and toward the lateral sides thereof to envelope the outsides of said passages and thereby to augment the heating of the air,

thence up the lateral sides and toward the center of the tunnel above the path of the ware and thence downwardly through the path of the ware to be recirculated by the air being introduced as aforesaid. v 10 21. Apparatus for annealing glassware, com prising an elongate tunnel, means for conveying glassware therethrough, said tnnnelincluding a first soaking zone starting at the entrance end in passing through which the temperature of the 15 ware is brought to and maintained at a desired point, a second annealing zone in passing through which the ware is caused to drop in temperature throughout its annealing range, and a cooling zone in which the ware is cooled to a desired 20 point, a muiile substantially coextensive in width with the tunnel associated with the soaking Zone thereof and below the path of the ware, passagesI extending from the muilie below the level of the path of the ware and adjacent to the lateral sides of the tunnel, means for supplying products of combustion to said muille and said passages, air pipes extending within said passages, means to cause a flow of air through said pipes to effect a counter-current preheating of the air, means to introduce at least a part of the air so preheated into the tunnel between said mufe and the path of the ware and in a direction toward the entrance end of the tunnel, and means for Yindependently controlling theitemperature gradient in the tunnel on opposite sides of a longitudinal median line thereof.

22. Apparatus for annealing glassware, comprising an elongate tunnel, means for conveying glassware therethrough, said tunnel including a first soaking zone starting at the entrance end in passing through which the temperature of the ware is brought to and maintained at a desired point, a second annealing zone in passing through which the ware is caused to drop in temperature throughout its annealing range, and a cooling zone` inl which the ware is cooled to 'a desired point, a muiile substantially coextensive in width with the tunnel associated with the soaking zone thereof and below the path of the ware, passages extending from the muiiie below the level of the path of the ware and adjacent to the lateral sides of the tunnel, means for supplying products of combustion to said mule and said passages, air

pipes extending within said passages, means to cause a flow of air through said pipes to effect a counter-current preheating of the air, means for introducing air so preheated into the tunnel below the path of the ware and toward the lateral sides thereof to envelope said passages and thereby to augment the heating of the air circulated in the tunnel and thence to flow up the sides and toward the center of the tunnel, thence downwardly through the path of the ware to be recirculated^ by the air being introduced, and 65 means for controlling the temperature gradient laterally of the tunnel including means for independentlyl,controllingv the air directed toward each side thereof and means for4 independently controlling the` amounts of heated gases passing 70 along the passages on the two sides of the` lehr;

23. Apparatus for annealing glassware, comprising an elongate tunnel, means for conveying glassware therethrough, said tunnel includingV 'a/4 first soaking zone starting at thwtran end in passing through which the temperature of .the ware is brought to and maintained at a' desired point, a second annealing zone in passing through which th'eware is caused to drop in temperature throughout its annealing range, and a cooling zone in which lthe ware is cooled to a desired point, a muiiie substantially coextensive in width v with the tunnel associated with' the soaking zone thereof and below the path of the ware, V, passages extending from the muille below the. level,

of the path of the ware and adjacent to the lateral sides of the tunnel, means for causing a flow of products of combustion through said munie and said passages, air pipes substantially concentric within said passages to form therewith heat heated into the tunnel below thev path of the ware and toward =the lateral sides thereof to envelope said passages and thereby to abstract heat therefrom, and Lthence to tlow up the sides of the tunnel and toward the 'center thereof above the for introducing another portion of the air so prepath of the ware, thence downwardly through the path of the ware to be recirculated by the inductive action of the air being introduced, means for independently controlling :the amount of air .Suppliedto the air pipes on opposite sides of the lehr, means forindependently controlling the amount of products of combustion passing through said' passages, means for independently controlling the amounts o f air introduced into thetnnel toward the entrance end on opposite sigles 'of center 'of the'tunnel, and meansin ',thgcooling portionof the-tunnel for abstracting heat from the l ware to bring it down to a desired temperature. l

DONALD G. MERRILL. l

CERTIFICATE, 0F CORRECTON. p Patent No., 2,155,781@ October 18, 1958. 'DONALD G. MERRILL. l

It s hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page Lp, second column, line lO, for the word "closed" read closer; and thatl the sad Letters PatentA hould be read with this' correction `therein that the same may conform to the record of the case in the Patent Office.

signed and -sealed this 6th day of December, A., D. 1953.

Henry Van Arsdale (Seal) Acting Commissioner -of Patents. 

